Rhododendron rootstock named ‘Rhodunter 149’

ABSTRACT

A new and distinct  Rhododendron  hybrid plant used as a rootstock that exhibits a high lime tolerance and vigorous growth.

Botanical classification: Rhododendron hybrid.

Varietal denomination: ‘Rhodunter 149’.

BACKGROUND OF THE INVENTION

The present invention comprises a new and distinct cultivar of Rhododendron hybrid used as a rootstock known by the varietal name ‘Rhodunter 149’. The new variety was discovered in Ahrensburg, Germany. The new variety is the result of a planned breeding program between an unpatented Rhododendron fortunei (female parent) and C.V. ‘Cunningham's White’ (unpatented male parent). ‘Rhodunter 149’ exhibits leaves and flowers that are more similar to its female parent than to its male parent. Additionally, ‘Rhodunter 149’ exhibits more vigorous growth when compared to its male parent. Further, the new variety differs from both parents in its improved tolerance to lime. In fact, such improved lime tolerance (no Fe-deficiency symptoms on soils up to 6.9 pH) distinguishes the new variety from other Rhododendron varieties known to the breeder. The flower color of the new variety starts out as a strong lilac at bud stage and opens into a light lilac color. Its female parent has mostly white and bright pink flowers, and its male parent has white flowers. The new variety and its female parent bloom with fragrant flowers one to two weeks later than its male parent. Finally, ‘Rhodunter 149’ is a compact, bushy shrub. ‘Rhodunter 149’ has been trial and field tested and has been found to retain its distinctive characteristics and remain true to type through successive propagations.

DESCRIPTION OF THE DRAWINGS

The accompanying photographic drawings illustrate a four year old plant of the new variety, with the color being as nearly true as is possible with color illustrations of this type.

FIG. 1 shows a view of a typical flowering plant of the new variety grown to a flowering plant; and

FIG. 2 shows a close-up view of the inflorescences of the new variety.

DESCRIPTION OF THE PLANT

The following detailed description sets forth the characteristics of the new cultivar. The data which defines these characteristics were collected by asexual reproductions performed via cuttings or in vitro culture carried out in Ahrensburg, Germany. The color readings were taken in natural daylight. The new variety was four years old when described, except where expressly stated otherwise. Color measurements were taken outside under natural daylight. Color references are primarily to The R.H.S. Colour Chart of The Royal Horticultural Society of London.

PLANT

-   Time to initiate roots: About 90 days at 22–25° C. -   Time to produce a finished flowering plant from a rooted cutting:     About 4 years in the field. -   Rooting habit: Compact root bales. -   Form: Spreading. -   Height: 50 cm at 3 years. -   Diameter: 40 cm at 3 years. -   Vigor: Strong. -   Branching habit: Compact. -   Disease, drought and pest resistance: No observations made to date. -   Trunk (at 4 years):     -   -   Diameter.—3 cm.         -   Height.—5 cm above soil.         -   Bark color.—Year one: 144A. Year two: From 144A to 175A.             Year three: 175A. Year four and older: 177B to between 197B             and 197C.         -   Texture.—Smooth with fissured bark.         -   Pubescence.—Absent.         -   Form.—Erect. -   Lateral Branches:     -   -   Diameter.—5–7 mm.         -   Internode length.—1–2 cm.         -   Texture.—Smooth with fissured bark.         -   Pubescence.—Absent.         -   Color.—Year one: 144A. Year two: From 144A to 175A. Year             three: 175A. Year four and older: 177B to between 197 B and             197C. -   Leaves:     -   -   Arrangement.—Alternate.         -   Length.—20 cm maximum.         -   Width.—7.5 cm maximum.         -   Shape.—Oblanceolate.         -   Apex.—Broad.         -   Base.—Tapering.         -   Pubescence.—Absent.         -   Color.—Upper surface: 147B for young leaves and 147A for             mature leaves. Lower surface: 147C for both young and mature             leaves.         -   Margins.—Entire.         -   Venation pattern.—Dense venation with a pronounced central             vein.         -   Vein color.—Upper surface: 144A. Lower surface: 145C.         -   Stipules.—None present.         -   Bracts.—None present.         -   Petiole.—Shape: Round with a flat upside. Length: 2 cm.             Diameter: 3–4 mm. Upper surface color: 144A. Lower surface             color: 144C.         -   Pedicel.—Length: 4 cm. Width: 2 mm. Color: 144C. -   Flower:     -   -   Natural flowering season.—Beginning of May until the end of             May in Northern Germany.         -   Form.—Widely funnel-shaped.         -   Arrangement.—Truss.         -   Lastingness of bloom.—Approximately three weeks; from the             beginning of May until the end of May.         -   Average number of blooms.—One bloom period per year.         -   Fragrance.—Typical of Rhododendron fortunei.         -   Buds (described before bursting).—Shape: Oblong. Width:             20 mm. Length: 40 mm. Color: 67A.         -   Spike.—Number of flowers per spike: 10–15. Length: 15 cm.             Diameter: 15 cm.         -   Corolla petals.—Shape: Widely funnel-shaped. Number: 7.             Length: 45–55 mm. Width: 80 mm. Apex: Round. Margin:             Undulate. Color: When opening: 67B. Fully opened (upper             surface): 74C to 74D. (lower surface): The external part is             84B, and the inner part is 84C.         -   Corolla throat.—Tube length: 20 mm. Color: 153A. Texture:             Velvety smooth.         -   Sepals.—None present (totally reduced).         -   Petaloids.—None present. -   Reproductive organs:     -   -   Stamens.—Number: 14. Length: 30 mm.         -   Anthers.—Shape: Normal Rhododendron type. Color: 161D.             Length: 25 mm.         -   Pollen.—Amount of pollen: Typical for a Rhododendron plant.             Color of pollen: 150D.         -   Pistil.—Number: 1. Style: Color: 160D. Length: 45 mm;             filiform. Stigma: Shape: Undivided. Color: 145A. -   Seeds:     -   -   Production.—Seed capsules mature in November when pollinated             in May.         -   Length.—2 mm.         -   Color.—164B.         -   Number.—Approximately 200 per capsule.

COMPARISON WITH OTHER RHODODENDRON CULTIVARS

‘Rhodunter 149’ differs from ‘Nova Zembla’ (not patented) in that ‘Rhodunter 149’ is lime tolerant while ‘Nova Zembla’ is not. ‘Rhodunter 149’ has an upright growth habit while ‘Nova Zembla’ has a broad sweeping growth habit. ‘Rhodunter 149’ is very stable and has strong shoots while ‘Nova Zembla’ has thinner and less strong shoots. ‘Rhodunter 149’ has elongated and oval leaves while ‘Nova Zembla’ has vaulted and concave leaves with a slightly twisted leaf apex. 

1. A new and distinct variety of Rhododendron hybrid plant, as is herein illustrated and described. 